(1) Field of the Invention
The present invention relates generally to a fiber optic hydrophone array, and more particularly to a fiber optic hydrophone array which uses a novel method of positioning and securing a hydrophone on an elongate support member.
(2) Description of the Prior Art
Fiber optic hydrophone arrays consist of a plurality of fiber optic hydrophones attached and supported by a central support member. A fiber optic hydrophone is typically constructed by winding one or more optical fibers on a rigid mandrel. Currently, such hydrophones are fabricated using tubular shaped mandrels. Thus, there is a need to fasten these tubular mandrels to a central support member in the construction of fiber optic hydrophone arrays.
For proper operation of the array, no air voids must be present between the interface of the (outer) tubular mandrel and the (inner) support member. Excessive noise and lost sensitivity result when the air voids are present. The length of the array is such that conventional injection molding methods would be impractical and very expensive. Furthermore, based on the research and development effort in fiber optic hydrophone arrays, design of the array requires that the spacing between each hydrophone be adjustable during the construction phase. Machined molds, even if length considerations were neglected, would require many different variations in this spacing. Using an undersized central member and filling the void between each hydrophone's mandrel and central support member would require a centering fixture and some method of sealing the area until the adhesive was cured in order to prevent the adhesive from dripping out.